Thomas Bayes (around 1701–1761) was an English Presbyterian minister who did maths as a hobby on the side — and accidentally became one of the most quoted thinkers in modern science. His big idea was almost lost forever: he never published it. A friend dug it out of his papers after he died.
Bayes worked out how to update a belief when new evidence arrives — the recipe we now call
Bayes seems to have been a shy, careful man who published almost nothing under his own name in his lifetime. His famous essay only reached the world because his friend Richard Price found it among his papers and sent it to the Royal Society two years after Bayes had died. So the theorem that carries his name was, in a sense, edited and rescued by someone else — and it took another century for mathematicians to realise just how powerful this quiet little idea really was.